Most field sports such as, for example, football (i.e., soccer) are played with two teams matched against each other. Each match is controlled by a referee and two assistant referees. The referee has full authority to enforce the laws of the game in connection with the match to which he or she has been appointed. (Federation Internationale de Football Association (hereinafter "FIFA") Laws of the Game, LAW 5 (1997 Ed.)). However, since the referee is an active element of the game--moving and following play while enforcing the laws of the game there are times when the referee is not in a suitable position to see an infringement or to properly decide the outcome of an infringement of the laws. Additionally, the referee may not have enough time to look away from the center of play to determine whether an infringement of any law has occurred off-play. For this reason, two assistant referees are sometimes provided. (FIFA Laws of the Game, LAW 6.)
Generally, the assistant referees observe the game from each sideline of the playing field and, more particularly, by moving up and down the sidelines following the play on the field. Each assistant referee is generally responsible for only one-half of the playing field. The duties of the two assistant referees, which are subject to the decision of the referee, are to indicate: (1) when the whole ball has passed out of the field of play; (2) which side is entitled to a comer kick, goal kick, or throw-in; (3) when a player may be penalized for being in an offside position; (4) when a substitution is requested; and (5) when misconduct or any other incident has occurred out of the view of the referee. (FIFA Laws of the Game, LAW 6). The assistant referees also assist the referee to control the match in accordance with the general laws of the game.
The manner by which assistant referees indicate the above-mentioned circumstances is to signal the referee by raising and displaying a hand-held flag. However, situations can arise when the raising and displaying of the flag is not seen by the referee. For example, distances of 50 meters or more may separate the referee from an assistant referee. Additionally, the location of the assistant referee and the flag may be difficult to discern for a number of reasons such as, for example, games played at dusk or night may offer poor lighting conditions, the varicolored backgrounds generated by spectators, banners, and flags which are often displayed in stadiums may at least partially camouflage the assistant referee and the flag, and the tempo of the game may be such that the referee does not have enough time to look away from the play of the game to the assistant referee to see if a referee signal is being indicated. Therefore, methods and devices which assist the referee to overcome these difficulties are desirable.